An X-ray fluorescent analysis is used for a qualitative analysis and a quantitative analysis of a sample by irradiating the sample with an X-ray emitted from an X-ray source, detecting an X-ray fluorescence which is a characteristic X-ray emitted from the sample by an X-ray detector, and then obtaining spectrums from the generated energy. The fluorescent X-ray analysis can be rapidly performed without destroying the sample, and thus widely used in a process and quality control or the like. In recent years, since a trace measurement can be performed with high-precision and high-sensitivity, the fluorescent X-ray analysis is expected to be used particularly as an analyzing method of detecting hazardous substances included in materials or composite electronic components.
A bottom-surface type apparatus which irradiates the sample with a primary X-ray from below is known as the X-ray fluorescence analyzer. Since a detector or the like is positioned below the sample, the bottom-surface type apparatus includes a transparent drop prevention plate disposed to a sample stage to prevent, for example, dropping a part of the sample when placing the sample. For example, JP-A-2011-203102 discloses an apparatus in which, while using a sample holder attached with a resin film such as a PET film called a Mylar film, a sample is put on the resin film, and the sample holder is placed to cover an opening of a base plate, and then, the sample is irradiated with an excited X-ray through the opening and the resin film.